Left Pulmonary Artery Hypoplasia Research Articles

The multiform sonographic spectrum of arterial duct in right aortic arch

To study the different characteristics of arterial duct (AD) in a series of prenatally detected right aortic arch (RAA). Out of 832 congenital heart diseases (CHD) referred to a tertiary center, 98 cases had RAA. Based on anatomical landmarks we identified 7 types of AD: type 1 left-sided, transverse; type 2 left-sided, vertical; type 3 from the underside of aortic arch (AA), vertical; type 4 right-sided, mirror-image “V”, transverse; type 5 right-sided, “H” shaped, transverse; type 6 bilateral; type 7 absent or unidentifiable. For each type of AD the incidence of associated major CHD was calculated and chi-square test was applied to verify the null hypothesis with significance level of p < 0.05. Type 1 occurred in 43% of cases including 4 with CHD and no cases with pulmonary outflow obstruction (POO). Symptoms of vascular ring were present in 41% of survivors. Type 2, 3 and 7 AD were associated with tetralogy of Fallot (TOF) or equivalents. No type 5 AD with CHD had POO and 3 isolated cases had asymptomatic hypoplasia of left pulmonary artery (LPA). Two type 6 AD had disconnection of LPA. Type 1 occurred more often as an isolated finding (p < 0.001), whereas types 2 (p = 0.0026), 3 (p = 0.0045), 4 (p = 0.0325) and 7 (p = 0.0001) were frequently associated with major CHD. In RAA, type 1 (U-shaped) is usually an isolated finding (p < 0.001) which includes all symptomatic vascular rings. POO is always present when the AD is vertical or absent but not when it lies on a transverse plane. Bilateral AD is rare and brings the risk of functionary loss of left lung if not identified.

Left Lung and Pulmonary Artery Hypoplasia: A Rare Case of Hemoptysis.

Pulmonary hypoplasia or agenesis is a rare congenital disorder that results in lung underdevelopment. This disease is usually found in children but rarely encountered in adults. We describe the case of an 84-year-old woman diagnosed with a unilateral pulmonary hypoplasia presenting simultaneously with left pulmonary artery hypoplasia. Due to this condition, the patient had a lifelong history of pulmonary infections that resulted in several bronchiectases in the affected lung. Moreover, the pulmonary artery hypoplasia led to the development of pulmonary hypertension and collateral circulation causing hemoptysis, giving rise to the patient attending the emergency department. Although we were able to medically manage the hemoptysis, it can be fatal and require surgical intervention. Hence, an early diagnosis is essential so that appropriate follow-up and prompt prevention and treatment of complications, such as pulmonary infections, hemoptysis and pulmonary hypertension, are achieved.LEARNING POINTSAlthough rare and typically associated with childhood, lung and pulmonary artery hypoplasia can in exceptional cases be present in adult life.The diagnosis of lung and pulmonary artery hypoplasia is challenging in adults as they can easily be mistaken for more common diseases.Symptoms and complications may be life-threatening, including dyspnea, hemoptysis, recurrent pulmonary infections and pulmonary hypertension.An early diagnosis is extremely important because it allows a close follow-up with consequent timely detection and treatment of serious complications, especially pulmonary hypertension.

Hypoplasia of left pulmonary artery: A rare congenital heart disease

Unilateral hypoplasia or absence of pulmonary artery is a rare pulmonary vascular anomaly that is usually associated with other cardiac anomalies like Tetralogy of Fallot or cardiac septal defects, but can also occur as an isolated anomaly. We present a case of 6-monthold infant who presented with recurrent respiratory tract infection. On work up, chest X-ray showed ipsilateral small hemithorax with hyperluscency in the left lung field. Findings were confirmed with 2D echocardiography and pulmonary angiography which were suggestive of hypoplasia of left pulmonary artery.

左肺動脈低形成を合併した肺癌の1切除例

左肺動脈低形成を合併した肺癌の1切除例

Fontan completion after external stenting of the left bronchus and intrapulmonary artery septation for left pulmonary artery hypoplasia

Tracheobronchial obstruction and unilateral hypoplasia of the pulmonary artery are serious barriers to successful Fontan completion. We describe a 5-year old girl with left bronchial obstruction, hypoplasia of the left pulmonary artery and a single ventricle (double inlet left ventricle). She had undergone external stenting to treat left bronchial stenosis at 3 years of age, bidirectional cavopulmonary anastomosis and Damus-Kaye-Stansel anastomosis at 4 years of age, intrapulmonary artery septation 1 year later and, finally, completion of the Fontan operation with excellent postoperative haemodynamics.

Comparison of Bilateral Pulmonary Arterial Level and Diameter in Transposition of the Great Arteries

In normal anatomy, the left pulmonary artery (LPA) is usually situated higher than the right pulmonary artery (RPA); however, transposition of the great arteries (TGA), the LPA is not always situated higher than the RPA. This study was performed to clarify the relative position of the RPA and the LPA in transposition of the great arteries (TGA) as well as the implications. We reviewed 101 angiograms of patients with TGA (age 4.1 ± 1.2 months). The width of the RPA, the LPA, and the pulmonary trunk (PT) were measured just before their first branch in the frontal view. They were classified into four groups according to the ratio between the RPA and the PT (RPA/PT). The initial courses of the LPA and the RPA were compared and defined according to their height in the frontal view, and the preferential flow (or not) to the RPA was recorded. The equation of hydrodynamics was applied to evaluate the bifurcation angle. Both PAs were the same size in all cases. Forty-eight patients (47.5 %) had a RPA/PT diameter ratio < 0.49. The LPA coursed higher than the RPA in the majority of cases (81 [80.2 %]); in a minority of cases the LPA and RPA were at the same level (6 [5.9 %]); and in some cases the RPA coursed higher than the LPA (14 [13.9 %]). Patients with a high degree of PA hypoplasia tended to have both PAs at the same level or a higher-positioned RPA. Autopsy (1 of 3 cases) showed a posterior ridge against the bronchus in the higher RPA. Hydrodynamic calculation showed that the greater the angle between the RPA/PT, the greater the preferential flow. Preferential flow to the RPA in TGA did not necessarily result in LPA hypoplasia before its first branch. Higher RPA position relative to the LPA was associated with greater flow in it against the posterior bronchus. This situation was more prevalent in patients with severe PA hypoplasia.

Early and Midterm Results of an Alternative Procedure to Homografts in Primary Repair of Truncus Arteriosus Communis

Repair of truncus arteriosus communis (TAC) in the neonatal and early infant period has become a standard practice. We report our experience on primary repair of TAC with a bovine pericardial-valved woven Dacron conduit as an alternative procedure to homografts, with a focus on early and midterm results. From January 2001 to December 2007, 15 patients with mean age 1.5 years (range 3 months to 8 years), underwent primary repair of simple TAC. Cases with cardiogenic shock, complex-associated cardiac lesions, or adverse anatomy of the truncal valve were excluded. The Collett and Edwards anatomical type classification of TAC was as follows: type I, 13 (87%); and type II, 2 (13%). Right ventricular outflow tract was reconstructed in all the cases with a bovine pericardial-valved woven Dacron conduit. Overall mortality was 6.6% (1 death due to severe pulmonary hypertension). At a mean follow-up of 31 months (range 6-51), there were no deaths (5-year actuarial survival 93.4%). Out of the 14 midterm survivors, three developed stenosis of the pericardial-valved woven Dacron conduit, but only one underwent interventional procedure including percutaneous balloon dilation with stenting for associated left pulmonary artery hypoplasia. The rate of patients with no surgical or percutaneous reinterventions performed because of obstruction of the right ventricular outflow tract reconstruction in the midterm (5 years) was 86%. Truncus arteriosus communis repair with a bovine pericardial-valved woven Dacron conduit can be performed with a very low perioperative mortality and satisfactory midterm morbidity, favorably compared with that reported for the use of homografts. Interventional cardiac catheterization may delay the time of reoperation for inevitable conduit replacement due to stenosis.

Staged Hybrid Left Pulmonary Artery Rehabilitation in Post-Fontan Left Pulmonary Artery Hypoplasia

Left pulmonary artery hypoplasia in the setting of Fontan circulation predisposes to pulmonary artery discontinuity. We describe a novel approach to correct post-Fontan left pulmonary artery discontinuity by a strategy to produce isolated left pulmonary artery growth, followed by a catheter-based reincorporation of the left pulmonary artery into the Fontan circuit.

Rat model of left pulmonary artery hypoplasia

To create an animal model of pulmonary artery hypoplasia, we banded the left pulmonary artery (LPA) of 9-week Sprague-Dawley rats. Pulmonary artery (PA) architecture was studied by internally casting with Microfil. After anesthetizing and orally intubating, we placed an LPA band via a left lateral thoracotomy and allowed the rats to recover. At various time points (usually 14 days), we injected Microfil into the main PA and sacrificed the animal. Lung tissue was cleared with ethanol and methyl salicylate, preserving the 3D architecture of the lungs. We evaluated the lungs grossly with a stereoscope at 0.63X, then took color Z-stacks of image planes at 4X and converted each image to monochrome. Using Metamorph software, we deconvolved the stack to create a single 2D image, which we then pseudocolored, bringing out the terminal processes of vessels filled with Microfil, allowing for counting and comparison. Post-LPA banding lungs compared grossly with the normal right lungs. The left pulmonary artery architecture was generally less dense and often had dropout peripherally. Terminal branches decreased by 23.1% in the banded vs. the unbanded lung (SE 6.1, N=6). This animal model of unilateral pulmonary artery hypoplasia induced in juvenile rats will allow for the study of angiogenic effects of growth factors, with the intention of translating this knowledge to humans with congenital heart disease.

Induction of pulmonary angiogenesis by adenoviral-mediated gene transfer of vascular endothelial growth factor

Background We hypothesized that gene transfer of vascular endothelial growth factor (VEGF) mediated by an adenovirus vector might induce pulmonary artery angiogenesis in a lamb model of pulmonary artery hypoplasia. Methods Thirteen fetal lambs had left pulmonary artery banding at 106 days of gestation. Following birth, 3 groups were divided: VEGF group (n = 5) and β-GAL group (n = 4) received an adenoviral vector encoding respectively for human VEGF165 and for galactosidase A. A control group (n = 4) had neither gene nor virus. Viral suspensions were selectively instilled in the left bronchus 6.5 days after birth. Five nonoperated lambs constituted the normal group. Euthanasia was performed at 30 days of age. Gene transfer was confirmed by blue coloration of left lung obtained with Xgal solution in an additional experiment. Histomorphometric evaluation was performed. All groups were compared with ANOVA test and paired test was used to compare right and left lung in each animal. Results Left lung was similarly hypoplastic in all operated lambs. Left pulmonary artery hypoplasia present in all operated groups was significantly less pronounced in VEGF group. The number of pleural arteries was similarly increased in left lung of all operated lambs. Left lung arterial density was higher in VEGF group than in all other groups. The percentage of parenchyma of left lung was lower in β-GAL group than in all others, partially returned to normal in VEGF group. Conclusions In this model, transbronchial VEGF gene transfer induces pulmonary angiogenesis, proximal pulmonary artery growth and contributes to lung parenchyma recovery.

A Case of Left Pulmonary Artery Hypoplasia in Adult

Unilateral hypoplasia of the pulmonary artery is an uncommon anomaly, which commonly develops in combination with congenital cardiovascular defects such as tetralogy of Fallot, patent ductus arteriosus and septal defect of atrium or ventricle, but may also present as an isolated lesion. We have recently experienced a case of the left pulmonary artery hypoplasia in adult by chance of during the general health screen, which diagnosed by chest X-ray, chest spiral CT, lung perfusion and ventilation scan, digital substraction angiogram and bronchoscopy, then presented hereby with the review of relevant literature.

Surgical Management and follow-up of vascular rings.

Thirty patients with aortic arch anomalies resulting in tracheo-oesophageal compression were treated during the period 1966 through 1987. These anomalies are important causes of upper respiratory and oesophageal obstruction in babies and small children. Although symptoms started within the first months of life in most cases, only 15 underwent surgery before six months and a delay of more than one year occurred in 5. Diagnosis was established by chest roentgenogram, barium oesophagogram and angiography. Thirteen (43%) patients had a double aortic arch, 9 (30%) cases had aberrant right subclavian artery and 6 (20%) patients had right aortic arch with ductus or ligamentum arteriosum. One (3.5%) patient had pulmonary artery sling and 1 (3.5%) case had right aortic arch and ductus arteriosum and aberrant right subclavian artery. Associated malformations were seen in 8 (27%) cases, (4 ventricular septal defects, 1 atrial septal defect, 1 coarctation of the aorta, 1 hypoplasia of left pulmonary artery, 1 left diaphragmatic eventration). Basic surgical procedure includes exposure through a left thoracotomy, complete identification of the anomaly and division of the constricting ring. 85% of the patients are asymptomatic and minimal to moderate stridor persists among the remainder. Severe tracheomalacia was responsible for the only two deaths in the series.